Disallow data when QNS switched the preference

When the preference has switched to another transport, do
not allow data setup. This avoid the case that data service
keeps asking telephony to retry while QNS already switched
the preference to another transport.

Test: Manual
Fix: 182899920, 175399007
Merged-In: I60401a1500ee1eed404f76020a648936784981a2
Change-Id: I60401a1500ee1eed404f76020a648936784981a2
(cherry picked from commit 6e19653d)